Search

The method of hypergraph containers, which was introduced several years ago by Balogh, Morris, and Samotij, and independently by Saxton and Thomason, has proved to be an extremely useful tool in the study of various monotone graph properties. In particular, a fairly straightforward application of this technique allows one to locate, for each non-bipartite graph H, the threshold at which the distribution of edges in a typical H-free graph with a given number of edges undergoes a transition from 'random-like' to 'structured'. On the other hand, for nonmonotone hereditary graph properties, the standard version of this method does not allow one to establish even the existence of such a threshold. In this paper we introduce a refinement of the container method that takes into account the asymmetry between edges and non-edges in a sparse member of a hereditary graph property. As an application, we determine the approximate structure of a typical graph with n vertices, m edges, and no induced copy of the 4-cycle, for each function m D m.n/ satisfying n4=3.log n/4 6 m n2. We show that almost all such graphs G have the following property: the vertex set of G can be partitioned into an 'almost independent' set (a set with o.m/ edges) and an 'almost-clique' (a set inducing a subgraph with density 1-a The lower bound on m is optimal up to a polylogarithmic factor, as standard arguments show that if n then almost all such graphs are 'random-like'. As a further consequence, we deduce that the random graph G.n; p/ conditioned to contain no induced 4-cycles undergoes phase transitions at p=n -2/3+o(1) p=n -2/3+o(1). [ABSTRACT FROM AUTHOR]

Vittorio Benussi (1878–1927) is known for numerous studies on optical illusions, visual and haptic perception, spatial and time perception. In Padova, he had a brilliant student who carefully worked on the topic of how people estimate numerosity, Silvia De Marchi (1897–1936). Her writings have never been translated into English before. Here we comment on her work and life, characterized also by the challenges faced by women in academia. The studies on perception of numerosity from her thesis were published as an article in 1929. We provide a translation from Italian, a redrawing of its 23 illustrations and of the graphs. It shows an original experimental approach and an anticipation of what later became known as magnitude estimation. [ABSTRACT FROM AUTHOR]

The carbide gradation related to geometry size and local stress concentration sensitivity significantly impacts the performance of the carburized 16Cr3NiWMoVNbE steel. The conventional metallurgical graphic comparison method by manual comparison is not capable of grading the carbide gradation automatically. A novel method is thus introduced to automatically evaluate the carbide grade by using a new shape factor φsc with stress distribution analysis instead of using the circularity or roundness shape factor which only considers the geometry shape of carbide particles. The logarithm of the stress concentration factor ln(K) is linearly related to the logarithm of the shape factor ln(φsc). The gradient b of the fitted straight line shows sensitivity to the carbide grade. The gradients are b1 = 0.039, b3 = 0.049, and b5 = 0.055 for the three carbide classes from low to high. Furthermore, there is also a linear relationship between hardness in different grades of carbide microstructure and the gradient b. [ABSTRACT FROM AUTHOR]

In this paper, a discrete model of delays at oversaturated intersections was established by using the graphic analysis method and a reward function. The problem of optimizing signal control at an oversaturated intersection was transformed into a Markov decision process by utilizing queue length as the state variable and choice of green ratio as the action. Following this, a self-learning method for signal optimization (SLSO) at oversaturated intersections based on deep learning (dueling Q-leaming, Dueling DQN) with priority experience replay (PER) was proposed. Moreover, dynamic learning rate and dynamic e-greedy strategy were used to accelerate convergence and achieve better model optimization. Constraints and penalties on queue length were set to avoid traffic overflow. The results of comparative simulations showed that the traditional method yielded the longest delay while the two-stage bang-bang control method led to the shortest delay, with a reduction in the delay of about 13.3%. The proposed SLSO could reduce the delay by about 12.3% and the maximum queue length by 1.7% without constraints on queuing, and by 5.1% and 13%, respectively, with constraints on queuing in place. Finally, a real-world 4-phase intersection was selected to prove that the proposed SLSO method is widely applicable. [ABSTRACT FROM AUTHOR]

Using a mixed methods approach, we explore a relationship between students' graph reasoning and graph selection via a fully online assessment. Our population includes 673 students enrolled in college algebra, an introductory undergraduate mathematics course, across four U.S. postsecondary institutions. The assessment is accessible on computers, tablets, and mobile phones. There are six items; for each, students are to view a video animation of a dynamic situation (e.g., a toy car moving along a square track), declare their understanding of the situation, select a Cartesian graph to represent a relationship between given attributes in the situation, and enter text to explain their graph choice. To theorize students' graph reasoning, we draw on Thompson's theory of quantitative reasoning, which explains students' conceptions of attributes as being possible to measure. To code students' written responses, we appeal to Johnson and colleagues' graph reasoning framework, which distinguishes students' quantitative reasoning about one or more attributes capable of varying (Covariation, Variation) from students' reasoning about observable elements in a situation (Motion, Iconic). Quantitizing those qualitative codes, we examine connections between the latent variables of students' graph reasoning and graph selection. Using structural equation modeling, we report a significant finding: Students' graph reasoning explains 40% of the variance in their graph selection (standardized regression weight is 0.64, p < 0.001). Furthermore, our results demonstrate that students' quantitative forms of graph reasoning (i.e., variational and covariational reasoning) influence the accuracy of their graph selection. [ABSTRACT FROM AUTHOR]

We have studied how first-year university science students construct graphs based on hypothetical qualitative physics scenarios. We gave students a questionnaire that asked them to complete two Cartesian graphs in one of three different scenarios (a ball rolling down a track, a beaker being filled with water, the resistance between different points on a metal bar) given as a written piece of text accompanied by a diagram of a hypothetical experiment that included three evenly spaced points on the set-up. Two of the three points were also indicated on the position axis of the partially drawn graph. We found that students can find it hard to translate equal spatial intervals in the experiment to a line graph. We found that most students either did not explain why they put the third point on the graph where they did, or did not plot the point at all. Some students drew unequal intervals on the position axis to indicate unequal time or resistance intervals. The difficulties became more prevalent as the levels of abstraction increased. Our findings suggest that constructing a scale on a qualitative graph requires significant mental effort from the students. [ABSTRACT FROM AUTHOR]

The process of a damaged ship flooding is a complicated free surface flow problem. There is a complex coupling effect between the ship cabin and the flow inside and outside of the cabin. In this paper, a GPU (graphic processing unit)- δ + -SPH (smoothed particle hydrodynamics) numerical model for the cabin flooding in deep-water environments is developed based on GPU parallel acceleration technology and Nvidia's CUDA (compute unified device architecture). First, the computational accuracy and efficiency of this numerical model are verified by experiments results on the water flooding of a simple damaged cabin model. Furthermore, the flooding characteristics of a submarine cabin are analyzed, considering different numbers of damaged cabins, depths, and opening positions. Finally, the progressive flooding and the dynamic response characteristics of a full-scale submarine model are investigated. The results show that the process of progressive flooding in a submarine cabin is characterized by its rapidity and intensity. Different factors, for example, damaged cabin numbers, cabin depths, and opening positions, have great influences on the process of flooding and the motion of the submarine cabin. This study can offer valuable technical assistance in the post-damage remediation process. [ABSTRACT FROM AUTHOR]

Air quality is an important environmental component that has a significant influence on public health and well-being. Poor air quality can cause a variety of health problems, including respiratory and cardiovascular disorders. Therefore, there is a growing demand for air quality prediction tools to enable consumers and authorities to take the best decisions and to implement the necessary actions to reduce air pollution. The present paper describes an innovative application that uses machine learning techniques to supply to the users real-time air quality predictions made on past data from their unique location. The Scikit-learn Python package was used to implement five machine learning algorithms, including K-Nearest Neighbors, Random Forest, Gradient Boosting, Support Vector Regression (SVR) and AdaBoost. To achieve robust model performance, compatibility with cross-validation approaches was evaluated. The obtained results indicate that these machine learning techniques are successful at forecasting air quality. The AdaBoost method emerged as the best accurate predictor after extensive investigation, closely followed by Gradient Boosting, SVR, Random Forest, and KNearest Neighbors. Furthermore, the investigation also focused on the adapted handling of inaccurate data and providing graphical visualizations to highlight the algorithm's efficacy. [ABSTRACT FROM AUTHOR]

The purpose of this narrative review is to study the problems in assessing visual acuity in deaf-mute children. We identified various methods of Visometry, published articles and patents for the inventions based on the assessment of visual acuity in deaf-mute children in the Russian Federation and parts of countries formerly part of the Soviet Union, in order to identify shortcomings and search for solutions. According to the total number of 126 cited scientific papers, the most common methods for assessing visual acuity in deaf--mute patients included Golovin-Sivtsev table (89.1%) and new JEI/JEI technique (8.9%). However, 2% of the doctors used tables of "illiterate" E, Teller Acuity cards with hand gestures, combining Teller Acuity cards with hand gestures to trigger reactions, Lea symbols with visual cues enabling visual cues or pointing to stimulate recognition and Graphic tables with sign language. In the presence of signs of hearing and speech disorders in patients, it is recommended to consider the use of cards duplicating optotypes to the table for assessing visual acuity [ABSTRACT FROM AUTHOR]

The article discusses tectonic stresses determined in the West Sakhalin terrain using different tectonophysical methods. The reconstruction of the stress field in coal fields in Sakhalin is implemented using the graphical method of orientation finding of stress axes in fractures and faults (at 16 observation points). The supplementary on-site tectonophysical studies made it possible to estimate the preferred orientation of the main slickensides of different kinematics and to reconstruct on this basis the local stress tensors at 53 observation points. The typical stress state of the West Sakhalin terrain is horizontal tension. [ABSTRACT FROM AUTHOR]

The objective of this article is to demonstrate the proficiency of a congenitally blind student in tactually interpreting accessible representations of a sector graph. The graph depicted in this study was extracted from a mathematics textbook in ink, subsequently rendered as a tactile graph generated with the Braille Fácil program, MONET software, and in manually crafted format using several materials, including EVA, Golden Beads, and various textures. The study focused on the examination of statistical graphical representations and the development of accessible materials for students with visual impairments, including those who are blind or have limited vision. More specifically, our research was centered on the creation of graphical-tactile materials. The study employed a qualitative methodology and utilized task-based interview techniques. Through this methodological tool, we delineated the profile of the participant and examined his approach to interpreting the tactile aspects of the graphic representations offered. [ABSTRACT FROM AUTHOR]

In this article, several optimization methods of two-electron repulsion integral calculations on a graphic processing unit (GPU) are presented. These methods are based on the investigations of the method presented by McMurchie and Davidson (MD). A new Boys function evaluation method for the GPU calculation is introduced. The series summation, the error function, and the finite sum formula method are combined; thus, good performance on the GPU can be achieved. By taking some theoretical study of the McMurchie–Davidson recurrence relations, three major optimization approaches are derived from the deduction of the general term formula for the Hermite expansion coefficient. The three approaches contain a new form of the Hermite expansion coefficients with corresponding recurrence relations, which is more efficient for one-electron integrals and [ss|∗∗] or [∗∗|ss] type two-electron integrals. In addition, a simple yet efficient new recurrence formula for the coefficient evaluation is derived, which is more efficient both in float operations and memory operations than its original one. In average, the new recurrence relation can save 26% float operations and 37% memory operations. Finally, a common sub-expression elimination (CSE) method is implemented. This CSE method is directly generated from some equalities we discovered from the general term formula other than by computer algebra system software. This optimized method achieved up to 3.09 speedups compared to the original MD method on the GPU and up to 92.75 speedups compared to the GAMESS calculation on the central processing unit. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new symmetric stream cipher encryption algorithm based on Graph Walks and 2-dimensional matrices, called Matrix Encryption Walks (MEW). We offer example Key Matrices and show the efficiency of the proposed method, which operates in linear complexity with an extremely large key space and low-resource requirements. We also provide the Proof of Concept code for the encryption algorithm and a detailed analysis of the security of our proposed MEW. The MEW algorithm is designed for low-resource environments such as IoT or smart devices and is therefore intended to be simple in operation. The encryption, decryption, and key generation time, along with the bytes required to store the key, are all discussed, and similar proposed algorithms are examined and compared. We further discuss the avalanche effect, key space, frequency analysis, Shannon entropy, and chosen/known plaintext-ciphertext attacks, and how MEW remains robust against these attacks. We have also discussed the potential for future research into algorithms such as MEW, which make use of alternative structures and graphic methods for improving encryption models. [ABSTRACT FROM AUTHOR]

One of the established trends in religion and international relations (IR) scholarship is the awareness of a rising level of religious discrimination against minorities. Although there is variation in rates, religious restrictions are widely observed across the globe, including in Western democracies. Scholarship on the restrictions on religious practices has advanced through seeking answers to the following questions: Who discriminates? Who is discriminated against more? What are the causes of restrictions on religious freedom? What are the forms of discrimination? The purpose of this article is to connect the theories and findings of two religious discrimination studies of IR via the graphic method of systemism. Featured works engage with religious discrimination in a sub-group of states—Western democracies and those with a Christian majority. While one study focused on government-based restrictions, the other one engaged with societal ones. Collectively, these works revealed the fragility of freedom and the importance of understanding the mechanisms that protect it. [ABSTRACT FROM AUTHOR]

This study aimed to investigate direct relationships of work addiction symptoms with dimensions of work engagement. We used three samples in which work addiction was measured with the Bergen Work Addiction Scale and work engagement was measured with the Utrecht Work Engagement Scale. One sample comprised responses from working Norwegians (n1 = 776), and two samples comprised responses from working Poles (n2 = 719; n3 = 715). We jointly estimated three networks using the fused graphic lasso method. Additionally, we estimated the stability of each network, node centrality, and node predictability and quantitatively compared all networks. The results showed that absorption and mood modification could constitute a bridge between work addiction and work engagement. It suggests that further investigation of properties of absorption and mood modification might be crucial for answering the question of how engaged workers become addicted to work. [ABSTRACT FROM AUTHOR]

In this article, we establish two new and different versions of fractional HermiteHadamard type inequality for the convex functions with respect to a pair of functions. Moreover, we establish a new Simpson’s type inequalities for differentiable convex functions with respect to a pair of functions. We also prove two more Simpson’s type inequalities for differentiable convex functions with respect to a pair of functions using the power mean and Hölder’s inequalities. It is also shown that the newly established inequalities are the extension of some existing results. Finally, we add some mathematical examples and their graphs to show the validity of newly established results. [ABSTRACT FROM AUTHOR]

In this paper, we find all repdigits which can be expressed as the sum of three Half- companion Pell numbers. To prove our main result, we use the combined approach of lower bounds for linear forms in logarithms of algebraic numbers and a version of the Baker Davenport reduction method. [ABSTRACT FROM AUTHOR]

A newly-disclosed non-standard finite difference method has been used to discretize a prey-predator model to investigate the critical normal form coefficients of bifurcations for both one-parameter and two-parameter bifurcations. The discrete-time prey-predator model exhibits variety of local bifurcations such as period-doubling, Neimark-Sacker, and strong resonances. Critical normal form coefficients are determined to reveal dynamical scenario corresponding to each bifurcation point bifurcation. We also investigates the complex dynamics of the model numerically using by MATLAB package MATCONTM based on numerical continuation technique. [ABSTRACT FROM AUTHOR]

In this article, we deal with a logarithmic wave equation with distributed delay. Firstly, we establish the well-posedness by utilizing the semigroup theory. Later, we obtain the global existence of solutions by using the well-depth method. Moreover, under appropriate assumptions on the weight of the distributed delay and that of strong damping, we get the exponential decay results. [ABSTRACT FROM AUTHOR]

A new approach for constructing vector Lyapunov function for nonlinear nonautonomous large-scale systems is proposed. It is assumed that independent subsystems are linear periodic systems. The components of the vector Lyapunov function are chosen as a quadratic form with a variable matrix. This matrix is an approximate solution of the Lyapunov matrix differential equation. This solution is constructed using the discretization method and the representation of the evolution operator proposed by Magnus. Sufficient conditions for the asymptotic stability of a trivial solution of a nonlinear large-scale system are established. The effectiveness of obtained results are illustrated by the example of stability investigation for coupled systems. [ABSTRACT FROM AUTHOR]

A simple theoretical model of network evolution is discussed here. In each step, we add a new vertex to the graph and it is allowed to connect it to maximum degree vertices (hubs) only. Given a constant p, the probability of such a connection is p for any hub. The initial (non-random) graph G1 is arbitrary but here we investigate mostly the case when G1 has one vertex. We solve here some particular cases of the problem, using enumeration methods. We obtain not limit theorems but exact results for the parameters discussed. [ABSTRACT FROM AUTHOR]

In this article is shown a path to define constants as well as input and output variables when elaborating a parametric model of an internal combustion engine by triggered ignition. There are discussed the different critical factors that should be considered when determining the constants and variables, this includes the engine operating conditions, the properties of the fuel and the emissions generated. In addition, there is also described the methods used to measure and validate these constants, variables, graphic methods and the different type of model founded. It concludes with the revision of the practical applications of the parametric model including its performance and concentration of the CO2 emissions to the environment. [ABSTRACT FROM AUTHOR]

We define a q-linear path in a hypergraph H as a sequence (e1,. . ., eL) of edges of H such that |ei nei+1| [[1, q]] and ei n ej = Ø if |i-j| > 1. In this paper, we study the connected components associated to these paths when q = k - 2 where k is the rank of H. If k = 3 then q = 1 which coincides with the well-known notion of linear path or loose path. We describe the structure of the connected components, using an algorithmic proof which shows that the connected components can be computed in polynomial time. We then mention two consequences of our algorithmic result. The first one is that deciding the winner of the Maker-Breaker game on a hypergraph of rank 3 can be done in polynomial time. The second one is that tractable cases for the NP-complete problem of "Paths Avoiding Forbidden Pairs" in a graph can be deduced from the recognition of a special type of line graph of a hypergraph. [ABSTRACT FROM AUTHOR]

Given a set system (also well-known as a hypergraph) H = {U, X}, where U is a set of elements and X is a set of subsets of U, an exact hitting set S is a subset of U such that each subset in X contains exactly one element in S. We refer to a set system as exactly hittable if it has an exact hitting set. In this paper, we study interval graphs which have intersection models that are exactly hittable. We refer to these interval graphs as Exactly Hittable Interval Graphs (EHIG). We present a forbidden structure characterization for EHIG. We also show that the class of proper interval graphs is a strict subclass of EHIG. Finally, we give an algorithm that runs in polynomial time to recognize graphs belonging to the class of EHIG. [ABSTRACT FROM AUTHOR]

Let t be a positive real number. A graph is called t-tough if the removal of any vertex set S that disconnects the graph leaves at most |S|/t components, and all graphs are considered 0-tough. The toughness of a graph is the largest t for which the graph is t-tough, whereby the toughness of complete graphs is defined as infinity. A graph is minimally t-tough if the toughness of the graph is t, and the deletion of any edge from the graph decreases the toughness. In this paper, we investigate the minimum degree and the recognizability of minimally t-tough graphs in the classes of chordal graphs, split graphs, claw-free graphs, and 2K2-free graphs. [ABSTRACT FROM AUTHOR]

We study the enumeration of inversion sequences that avoid pattern 021 and another pattern of length four. We determine the generating trees for all possible pattern pairs and compute the corresponding generating functions. We introduce the concept of d-regular generating trees and conjecture that for any 021-avoiding pattern, the generating tree T ({021; τ) is d-regular for some integer d. [ABSTRACT FROM AUTHOR]

In the Maker-Breaker domination game played on a graph G, Dominator's goal is to select a dominating set and Staller's goal is to claim a closed neighborhood of some vertex. We study the cases when Staller can win the game. If Dominator (resp., Staller) starts the game, then γSMB(G) (resp., γ′ SMB(G)) denotes the minimum number of moves Staller needs to win. For every positive integer k, trees T with γ′ SMB(T) = k are characterized and a general upper bound on γ′ SMB is proved. Let S = S(n1,..., nℓ) be the subdivided star obtained from the star with ℓ edges by subdividing its edges n1 - 1,..., nℓ - 1 times, respectively. Then γ′ SMB(S) is determined in all the cases except when ℓ ≥ 4 and each ni is even. The simplest formula is obtained when there are at least two odd nis. If n1 and n2 are the two smallest such numbers, then γ′ SMB(S(n1,..., nℓ)) = ⌈log2(n1 + n2 + 1)⌉. For caterpillars, exact formulas for γSMB and for γ′ SMB are established. [ABSTRACT FROM AUTHOR]

The bivariate chromatic polynomial χG(x, y) of a graph G=(V, E), introduced by Dohmen-Pönitz-Tittmann (2003), counts all x-colorings of G such that adjacent vertices get different colors if they are ≤y. We extend this notion to mixed graphs, which have both directed and undirected edges. Our main result is a decomposition formula which expresses χG(x, y) as a sum of bivariate order polynomials (Beck-Farahmand-Karunaratne-Zuniga Ruiz 2020), and a combinatorial reciprocity theorem for χG(x, y). [ABSTRACT FROM AUTHOR]

Face irregularity strength under ρ-labeling ξ with class (α1, β1, γ1) of plane graphs is a labeling from the set of graph elements into the set of integers, that is, ξ: {V ∪ E ∪ F} → {1, 2, 3, .., ρ}, such that the face weights are distinct at any stage in the graph labeling, that is, Wξ(α1,β1,γ̸1)(f) = Wξ(α1,β1,γ1)(g), for any two faces f and g of the graph G. The face irregular strength of a plane graph G is the least possible integer ρ such that G admits face irregular ρ-labeling. In this research, authors have examined the exact tight lower bounds for the face irregular strength of generalized plane graphs under ρ-labeling of class (α1, β1, γ1) for vertex (1, 0, 0), edge (0, 1, 0), face (0, 0, 1), vertex-face (1, 0, 1), edge-face (0, 1, 1) and entire (1, 1, 1). Results are verified by examples. [ABSTRACT FROM AUTHOR]

Flexoelectricity is an electromechanical phenomenon produced in a dielectric material, with or without centrosymmetric microstructure, undergoing a non-uniform strain. It is characterized by the fourth-order flexoelectric tensor, which links the electric polarization vector with the gradient of the second-order strain tensor. Our previous work [H. Le Quang and Q.-C. He, Proc. R. Soc. A 467, 2369 (2011)] solved the fundamental theoretical problem of determining the number and types of all rotational symmetries that the flexoelectric tensor can exhibit. In the present study, compact explicit matrix representations of the flexoelectric tensor are provided so as to facilitate the use of it with any possible rotational symmetry. The number and types of all reflection symmetries that the flexoelectric tensor can have are also determined. To identify the rotational symmetry and reflection symmetry of a given flexoelectric tensor, a simple and efficient graphic method based on the concept of pole figures is presented and illustrated. [ABSTRACT FROM AUTHOR]

The paper talks about the facts that were established in the research of the origin of fruits and vegetables in the markets of Novi Sad. The results of the research are presented using graphic and cartographic methods. Observed illogicalities are clarified in communication with consumers and sellers. The obtained results were compared with foreign works. One of the goals of the work was to determine the extent of suburban agriculture, which should be the most competitive with others further away from the city. Economic factors have a decisive influence from where the city will be supplied with fruits and vegetables. [ABSTRACT FROM AUTHOR]

Research on the related analysis tasks of graph representation methods was carried out, starting from the formal definition, divide graph representation learning methods into five categories with different core technologies as the classification criteria, including dimensionality reduction analysis, matrix decomposition, random walk, neural network and other representation learning methods. Secondly, through induction and comparative analysis, the paper combed the development context of various technologies, and then showed the advantages and disadvantages of various graphic representation methods in a deep level. Then combined with the inductive analysis of common data sets, evaluation methods and application fields of graph representation learning, it carried out the four-dimensional analysis of dynamics, scalability, interpretability and analyticity. Finally, it summarized and looked forward to the future research trends and development directions of graph representation learning [ABSTRACT FROM AUTHOR]

This article brings a broad array of works, which pertain to different research areas of international relations (IR), into contact with each other via a graphic method, systemism, to obtain insights that otherwise might prove elusive. Completion of these tasks is anticipated to exemplify how the systemist approach can enhance communication throughout IR. Systemism is introduced as a graphic technique for communicating arguments. Systemist graphics are used to convey the contents of (a) two studies that focus on theory per se and (b) a range of topics—foreign policy analysis, forecasting, and conflict processes. Systematic synthesis focusing on the two works about theory and bricolagic bridging that is based on all five studies reveal the contributions of a systemist approach, respectively, to the logics of confirmation and discovery. Value added from the systemist approach is confirmed for both IR research and pedagogy. [ABSTRACT FROM AUTHOR]

Computer‐supported collaborative learning (CSCL) has been an effective pedagogy in the field of education. However, productive collaborative learning often does not occur spontaneously, and learners often have difficulties with collaborative knowledge building and socially shared regulation. To address this research gap, this study proposes an automatic knowledge graph construction approach based on deep neural network models. In total, 63 groups comprising 189 college students participated in this study and were assigned to three conditions, namely, the automatic activated and unactivated knowledge graph (AAUKG) condition, the automated activated knowledge graph (AAKG) condition, and the traditional online collaborative learning (TOCL) condition. The findings revealed that the AAUKG approach had more significant and positive impacts on collaborative knowledge building, group performance, social interaction, and socially shared regulation than the AAKG and TOCL approaches. This study provides substantial evidence of utilising both automatically activated and unactivated knowledge graphs to improve collaborative learning performance. Practitioner notesWhat is already known about this topic Knowledge graphs have been widely used in many fields for searches, recommendations, analytics, and automation.Researchers have explored how to construct knowledge graphs. However, few studies have automatically constructed knowledge graphs in the CSCL context.What this paper adds An automatic knowledge graph construction approach is proposed and validated in the CSCL context.The findings indicate that the AAUKG approach has more significant and positive impacts on collaborative knowledge building, group performance, social interaction, and socially shared regulation than the AAKG and TOCL approaches.Implications for practice and/or policy The AAUKG approach is an effective method for improving knowledge building and group performance in the CSCL context.Researchers and practitioners are encouraged to consider how knowledge graphs can be applied to facilitate collaborative learning efficiently. [ABSTRACT FROM AUTHOR]

The averaging of waveforms necessary to detect small cortical evoked potentials which was pioneered by George Dawson, and the periodicity of component waves resulting from interference identified by Thomas Young, reveal selected components of the visual record to be diminished and others to be enhanced and thus salient. Surprisingly, these examples of achieving salience in neurophysiology and physics were anticipated two millennia ago by the Greek artist Zeuxis. When commissioned to paint a portrait of Helen of Troy, Zeuxis used a not dissimilar method of selection which still resonates today in the carnal artistry of Orlan. These examples reveal the important contribution of graphic methods to the depiction and hence the significance of salience in both the sciences and the humanities. [ABSTRACT FROM AUTHOR]

Recent debates on 'graphic' geographies and the reinterpretation of the notion of 'democratic experimentalism' in local development suggest the rise of a new 'representational experimentalism' that explores graphic methods for place‐based approaches. Graphic methods of research can assist geographers in conducting and presenting the results of place‐based research to wider audiences. Graphic products of research function as tools for storytelling and spatial planning. They can also provide intersubjective dialogue between researchers, local communities, and local governments to create more inclusive place‐based narratives. In this paper, we present a verbo‐visual manifesto and an illustrated fieldwork journal as two empirical examples of possible ways to engage with graphic methods and realise the potential graphic outputs of research. These graphic products are the result of a collaboration between geographers, students in Local Development and Sustainable Territorial Development (at the University of Padua), two professional illustrators, and a group of local stakeholders; they used scribing and observational drawing as place‐based graphic methods during a residential seminar at the Po Delta, in north‐eastern Italy. This paper contributes to both recent debates on creative methods in local development and the study of the use graphic and visual methods in geography. It proposes graphic methods as a way for embracing place‐based approaches to local development in peripheral, fragile, and contested areas, making hidden voices visible. [ABSTRACT FROM AUTHOR]

This paper presents methods for the precise orbit determination (POD) of a satellite in the CYGNSS constellation based on available single-frequency GPS code and carrier measurements. The contributions include the development and evaluation of procedures for single-frequency POD with GipsyX, improvement of CYGNSS orbit knowledge, and an assessment of its final accuracy. Ionospheric effects are mitigated using the GRAPHIC processing method, and spacecraft multipath effects are calibrated with an azimuth/elevation-dependent antenna calibration map. The method is demonstrated using comparable data from the GRACE mission, from which we infer the expected accuracy of the CYGNSS results. Processing more than 170 days of data from each mission, a 1 σ CYGNSS orbit accuracy of 2.8 cm radial, 2.4 cm cross-track, and 6 cm in-track is demonstrated. We expect that achieving this level of performance will expand the set of future scientific investigations that can be undertaken using satellites equipped with single-frequency GNSS. [ABSTRACT FROM AUTHOR]

We continue the study of the properties of graphs in which the ball of radius r around each vertex induces a graph isomorphic to the ball of radius r in some fixed vertex-transitive graph F, for various choices of F and r. This is a natural extension of the study of regular graphs. More precisely, if F is a vertex-transitive graph and r ∈ ℕ, we say a graph G is r-locally F if the ball of radius r around each vertex of G induces a graph isomorphic to the graph induced by the ball of radius r around any vertex of F. We consider the following random graph model: for each n ∈ ℕ, we let Gn = Gn (F, r) be a graph chosen uniformly at random from the set of all unlabelled, n-vertex graphs that are r-locally F. We investigate the properties possessed by the random graph Gn with high probability, i.e. with probability tending to 1 as n → ∞, for various natural choices of F and r. We prove that if F is a Cayley graph of a torsion-free group of polynomial growth, and r is sufficiently large depending on F, then the random graph Gn = Gn (F, r) has largest component of order at most n5/6 with high probability, and has at least exp(nδ) automorphisms with high probability, where δ > 0 depends upon F alone. Both properties are in stark contrast to random d -regular graphs, which correspond to the case where F is the infinite d -regular tree. We also show that, under the same hypotheses, the number of unlabelled, n-vertex graphs that are r-locally F grows like a stretched exponential in n, again in contrast with d -regular graphs. In the case where F is the standard Cayley graph of ℤd, we obtain a much more precise enumeration result, and more precise results on the properties of the random graph Gn (F, r). Our proofs use a mixture of results and techniques from geometry, group theory and combinatorics. We make several conjectures regarding what happens for Cayley graphs of other finitely generated groups. [ABSTRACT FROM AUTHOR]

Peirce's beta graphs are roughly equivalent to our first-order predicate logic. However, Bellucci and Pietarinen have recently argued that the beta graphs are not well-equipped to handle asymmetric relative terms. I survey four proposed solutions to the problem and find them all wanting. I offer a fifth solution according to which Peirce's beta graphs function at three different levels of abstractness from natural language. I diagnose the problem of asymmetric relative terms as arising when we transition from the first to the second level of abstractness. Making grammatical information encoded in natural language explicit at the first level of abstractness and interpreting graphs at the second level of abstractness as shorn of grammatical information resolves the problem. The solution is both well-motivated by Peirce's own commitments and increases the expressiveness of the beta graphs. [ABSTRACT FROM AUTHOR]

Capitalizing on the tourist potential of a region together with the presence of roads and means of transport to areas with potential generates numerous tourist flows that will contribute to the tourist development of that geographical part of the country. The tourist technical-material base adapted to the needs and standards of tourists will contribute to a high number of overnight stays in the tourist region. The data processed in the work come from National Institute of Statistics-NIS. The qualitative aspects in this research were studied based on current scientific literature, official documents and observation method, and the quantitative research was carried out using statistical analysis of the processed data, graphic and cartographic method, the method of observation and interpretation. The results were presented in tables, graphs and then interpreted and examined. Data used in this study are part of the textbook on the desk. Tourist reception structures are the most important part of the technicalmaterial base of tourism. The tourist accommodation units include public utility spaces classified and arranged in such a way as to allow the accommodation of tourists and the provision of specific services according to the location. Despite that the most numerous accommodation units are represented by hotels, their number declined from 2,100 in 2008 to 1,526 in 2020 (-17.4%). The number of overnight stays is also high in hotels, but they also decreased from 52,481 in 2008 to 22,368 in 2020 meaning by - 67.4% less. A number of 304,068 tourists visited Ialomita county in 2008 and 73,697 in 2020, which reveals 24.2% because the county is visited especially for spa treatment in Amara Resort. The more active involvement of the authorities and the population for competitive activities and the increased degree of responsibility for everyone will generate a sustainable development of the region. [ABSTRACT FROM AUTHOR]

The development of information technologies, which has led to an increase in the amount of multimedia content in World traffic, makes the role of the steganographic component in modern information protection systems significant. At the same time, to ensure steganographic protection of information in real-time when operating with digital video, the steganographic method is expected to meet the main effectivity criteria, as well as provide a low level of computational complexity, which is possible when performing steganographic transformation in the spatial domain of the container. One such modern method is the steganographic method with code control of additional information embedding. The problem of increasing the robustness of the specified steganographic method in the conditions of compression attacks by compression algorithms of digital video, primarily, the widespread MPEG-4 algorithm, is of particular interest. The purpose of this paper is to increase the robustness against attacks by compression of the steganographic method with code control of additional information embedding when operating with digital video. In this paper, experimental research on the robustness of the steganographic method with code control of additional information embedding in the conditions of a co mpression attack against the emb edded message by digital video compression algorithm MPEG-4 when embedding information using different colour models is performed. It is shown that embedding additional information in the Y-component of the YCbCr colour model allows reducing the number of errors when extracting additional information by 17%. It is also proposed to embed additional information using the steganographic method with code control only in dynamic blocks, which made it possible to reduce the number of errors when extracting additional information by 8%. The obtained results can be applied in practical steganographic applications to increase the robustness of the applied steganographic component of information protection systems. [ABSTRACT FROM AUTHOR]

A considerable analysis has been performed to draw out the flow properties of MHD Casson fluid in parabolic movement with several parameters. The novelty in the examination is the angle of inclination with the permeable vertical plate. The purpose of the work is to analyze the impact of some parameters on the flow in two cases namely, obtuse angle and acute angle. The solution of the flow governed equations is attained by the utilization of the finite divergence technique in explicit type. The nature of the fluid velocity is observed in the cases of acute angle and obtuse angle and described accordingly with the use of graphs and tables. One of the major findings is that for increasing values of porosity the velocity enhances in the case of acute angle and falls down in the case of obtuse angle. [ABSTRACT FROM AUTHOR]

A 2-rainbow dominating function on a graph G is a function g that assigns to each vertex a set of colors chosen from the subsets of f1; 2g so that for each vertex with g(v) =; we have S u2N(v) g(u) = f1; 2g. The weight of a 2-rainbow dominating function g is the value w(g) = P v2V (G) jf(v)j. A 2-rainbow dominating function g is an independent 2-rainbow dominating function if no pair of vertices assigned nonempty sets are adjacent. The 2-rainbow domination number r2(G) (respectively, the inde-pendent 2-rainbow domination number ir2(G)) is the minimum weight of a 2-rainbow dominating function (respectively, independent 2-rainbow dominating function) on G. We prove that for any tree T of order ≥ 3, with l leaves and s support vertices, ir2(T) ≤ (14n + ' + s)=20, thus improving the bound given in [Independent 2-rainbow domination in trees, Asian-Eur. J. Math. 8 (2015) 1550035] under certain conditions. [ABSTRACT FROM AUTHOR]